Roman blinds rely on the use of battens which extend from selvedge to selvedge in the blind fabric. Each batten has a series of eyes through which vertical control lines pass and these lines cause rise and fall in the blind. The battens are commonly aluminium extrusions and these attach to the fabric. One type of blind construction is described in our co-pending patent application no. 2006903061.
The extrusion in that specification had a pair of sidewalls which defined a fabric slot. The assembled blind housed a 2-3 mm diameter plastic rod which imprisoned a loop of fabric in the slot. End caps confined the rod and stabilised the structure. The extrusions are powdercoated and cut from stock lengths by a parting tool. This leaves the ends with sharp edges. During the assembly process the fabric is creased to create a loop of double thickness and the extrusion is slid across the fabric so that the crease enters the fabric slot. The sharp ends abrade the fabric and damage occurs unless the assembly is slow and careful. Consequently assembly is slow even with experienced assemblers.